Translucent sparn-plug intensipier



April 13 1926. 1,580,562

H. D. MOORE I TRANSLUCENT SPARK PLUG INTENSIFIER Filed April 11, 1925Inventor. Henry D. Moore Attys.

Patented Apr. 13, 1926.

'of the spark plug;

UNITED STATES I, 1 1,580,562 PATENT- OFFICE.

HENRY n. MOORE, or Bosrom'MAssRcHusEfis, assiqiton 1-0 name 1). BAKER,

or msssacrrtismrsj mansnucmwr SPARK-PLUG immwsn rmy Applicat'ion filcd'Aili'il 11,

To all whom it may concern:

Be it known that I, HENRY D. Moons; a citizen of the United States andresident of Boston, county of Suffolk, State of Massachusetts, haveinvented an Improvement in Translucent Spark-Plug Intensifiers,' ofwhich the following description incon'nection with the accompanyingdrawing, is a specification, like characters on the drawing representinglike parts.

This invention relates to a spark intensifier and the object thereof isto provide;- a

novel spark intensifier of the type forming a gap in the circuit wire ofa spark plug.

A further object of the-presentinvention is to form such a sparkintensifier in -which the auxiliar-y spark gap is visible. I

A further object of the present invention is to provide an electric-allyinsulating-translucent spark plug cap havingan aperture therein whichforms a spark gap and aninclosed visible spark chamber.

A further object of thepresen-t invention is to provide aglass sparkplug cap form-ing an auxiliary spark gap.

Other objects and features of the inven: tion will more fullyappear'from the following description and the accompanying draw-- ingsand will be particularly pointed out in the claims.

In the drawings:

Fig. 1 is an elevation'of; the spark intensifier applied to a spark plugwith meanson the intensifier for engaging thespark plug electrodetoretain the intensifieronthe spark plug;

F ig. 2 is a vertical section through the intensifier and the top, ofthe spark plug shown in Fig. 1;

Fig. 3 is a section on line 3-3 Fig. 2;

Fig. 4 is a section similar to: Fig. 3 but showing different means forretaining the terminal of the spark plug lead wire on the intensifierFig. 5 is an elevation of the intensifier with minor detail changesapplied to the end Fig. 6 is a section on line 66' Fig. 5.

The device illustrated herein is designed to beused in conjunction withan electric circuit havin therein a spark ap. It is particularlydesignedto be used in the cir} euit wire of a s ark plug on an internal combstion engine to form a spark dgap auxiliary to the spark gap on the anof 1923. Serial No. 631,274.

the'plu-g which lies in the cylinder of the is desirable to' permit theoperator of the engine actually to see, during the period when theengine is" runi ing, that current s flowing through the circuit wire ofthe spark plug by seeing the spark jump across the a'uxiliarysparkgap-in the visible chamher and thus assure himself that, should theenginebe running 'i-rregi'ilarl-y; the

trouble does not lie in the ignition system v between the magneto, orother source of high voltage current. and the plug.

As] illustrated herein't he: device consists of an electricallyinsulating translucent bulb 1 made of any suitable material,-such forinstance as glass. having an aperture' 2 vtherein, act-ing to. provide apath for the current across a separating gap and to form an incl'osedvisible spark chamber. The wire of theelectric circuit illustratedherein comprises the: spark plug electrode 3 and terminal 5. V V.

In the form of device" illustrated in Figs. 1 to 4 incl'usively the bulbI made in the form of an electrically insulating translitcent sparkplugcap presenting a groove 6 on its periphery to receive, and'supporttheterminal 5 of the spark plug'lead wire-and the aperture, 2 has} one end!communicating with said groove. "Anopening 7- communicates with thevaperture and houses, the end of the electrode 3- which projects abovethe spark plugin the usualnmanner. The aperture 2 is formed at such aheight above! the base 8 01% the capft-hat the terminal of; the

the sparkplug lead wire 4- which has" a electrode lies adjacent one endof said aperture. For convenience in making, the aperture extendsentirely through the cap forming two apertures and the opening 7communicates with the inner end of each while the terminal 5 of thespark plug lead wire has portions lying adjacent to the outer end ofeach of said apertures. The terminal 5 may have either the form shown inFig. 3

cap for retaining the cap on the spark plug. Such a means is shown atQFigs, land 2 and consists of a section of any suitable material,preferably metal, which is spun on the glass cap and has a section 10embracing the outer periphery of the bottom of the cap and a section 11which extends into the opening 7 to engage the terminal oi the electrode3.

The form of the device shown in Figs. 5 and 6 is the same in allessentials as that shown in F 1 and 2. In both forms the cap acts tohold the electrode and the terminal of the spark plug lead wire inspaced and insulated relation and the aperture acts to provide apath torthe current between said electrode and said terminal and to form anenclosed visible spark chamber. The. cap itself has, however, been madein a slightly different shape in order to permit the use of another formof means to retain on the cap the terminal of the lead wire. In thisform of cap the aperture 2 does not go entirely through the cap butmerely extends as tar the opening 7 which houses the electrode The capis formed with a projection 12 thereon having a reduced neck 13connecting said projection with the main body of the cap and aperture 2extends through both the projection and the reduced neck. The means forretaining the lead wire on the cap is preferably a metal sleeve 1 1, ofa size closely to embrace the insulation 15 oi? the lead wire, with areduced end 16 which fits over the projection 12 and around the reducedneck 13 to retain the sleeve on the cap. The end of the sleeve lyingaway from the cap is turned inwardly as shown at 17 to bite into theinsulation of the lead wire and thus hold the terminal of the lead wire,which in this case is the bare end of the wire itself, adjacent the endof the aperture. Wit-h this form of device the nut 18 ordinarilysupplied with the spark plug is used to retain the cap on the plug.

Thus the device in either form illustrated is adapted to fit over theelectrode of any ordinary spark plug without alteration of the sparkplug construction. In the form shown in" Figs. 1 to'at the usual nut onthe spark plug is discarded and the device is itself provided with meansfor holding it in position on the spark plug while in the form shown inFigs. 5 and 6 the device is made thinner and the usual nut acts as theretaining means.

From the above description it will be seen that the spark intensifierwhich forms the subject matter of this invention is extremely simple andcan be cheaply manufactured.

Having thus described the invention, what is claimed as new, and desiredto be secured by Letters Patent is:

1. An electrically insulating, translucent,

solid, integral spark plug bulb having an opening to fit over the sparkplug electrode and having an aperture communicating with and extendingtransversely of the opening, the spark plug electrode lying adjacent oneend of the aperture and the terminal of the spark plug lead wire lyingadjacent the other end of the aperture when the bulb is in cosh tion.onthe spark plug electrode, whereby the bulb acts to hold said electrodeand said teminal in'spaced and insulated relation and the aperture actsto provide a path for the current between the electrode and the terminaland forms an inclosed visible spark chamber.

2. An electrically insulated translucent spark plug cap presenting agroove on its periphery to receive and support the. terminal of thespark plug lead wire, having an aperture with one end communicating withsaid groove, and having an opening communicating with the aperture tohouse the spark plug electrode adjacent the end of said aperture wherebythe aperture will act to provide a path for the current across the gapbetween the electrode and the lead wire terminal and to form an inclosedvisible spark chamber.

In testimony whereo i, I have signed my name to this specification.

HENRY D. MOORE.

